GT2 Evo Cams on a 930--the result

[Bruce M.]

A few days ago, I posted a question about these cams, asking for input as to whether to switch to them. Well, I'm staring at the dyno sheets right now. Check this out:

3 readings, at 1.0, 1.2 and 1.4 bar. Ambient temperature 80 degrees. 110 gas. All numbers are peak unless otherwise stated.

1 bar: 634 hp at 6800 rpm. 510 ft. lbs at 6300 rpm. I'm at 300 ft lbs at 3300 rpm, and at 400 by 4000.

1.2 bar: 668 hp at 6400 rpm. 600 ft lbs at 5500 rpm. Developing 500 ft lbs at 4000 rpm.

1.4 bar: 705.8 hp at 6000 rpm. 627 ft-lbs at 5400 rpm.

Nothing new in this engine from my previous runs other than the cams. Peak power went up by almost 60 hp, and 20 ft lbs.

I think this was the right way to go....

JUst FYI, there is NO WAY I'm going to run this car at 1.4 bar. Couldn't afford the new tires every week, and I'd like to stay alive to boot. But 1 bar I'll do, and maybe 1.2 with race gas on the track.

[NYSCAR]

good gawd!!!!

those are rear wheel #'s!?!??!

What in the heck did you do to that thing? And what kinda transmission you have putting those horsies to the ground?

Brad

[Bruce M.]

Nope. Glad you asked. They are at the crank. Drivetrain loss has proven in the past on this car to be ust under 14%.

Stock 930 tranny. 935 pressure plate. ZF-style LSD at 80% lock.

[CamB]

Bruce

While I agree the dyno numbers are a good indication of the impact of the cam change, the only real way I will be satisfied you have got a suitable performance gain is to drive the car myself. Preferably for a few days, maybe a couple of weeks

Seriously, the +60hp is a good data point for those considering the swap. How did the driveability change (if at all).

And you surely must be the horsepower-junkiest... always 600hp+... unbelievable.

[Bruce M.]

I'll tell you about the driveability when I get the engine back in the car and drive it. Looking forward to that day....

I do dig horsepower, but actually we're in the tire-liquefying, death-defying area now. I'm getting too old.. .

I'm a classic "victim" of the "while we're in there" syndrome.

The grooviest thing about the car to me, though, is that it is totally driveable around town, on the freeway, etc. Sips gas on cruise (much better than the CIS system). Totally docile car. Until your right foot twitches...

[jkcrewsn]

Is there another post somewhere that lists all the mods done to the engine. That is some serious power. I'm insanely jealous. But then again, I most likely wouldn't be able to afford it anyway. Guess thats what jealousy is all about, eh?

[kstar]

Holy Schmoley!!

Just when I was feeling high about my motor I read your post!

That is truly amazing and I bet that thing will feel like a true rocket when it spools up!!!

. . . but I guess it probably already did before the additional 60hp.

Best to you,

Kurt

[juan ruiz]

BRUCE
I Remenber you asking about them, and I was one of them who replay to go for !! as I sit here and read the results I found my self with a little tear running down my face since my car is going thru the surgery! I too will have those EVO GT 2 Cams on my 3.2 turbo well it will be a 3.3 Turbo,so if you got +60 hp I am already adding them to my 320hp + 60 hp=380hp,oh yes 120 hp more and I be Ready! Congratulations! Hey next time Post this staff under HP Junkies Theres MANY PEOPLE reading but only a few of us have the same symdrome but we keep them on the On the EDGE !!!!
HP=
Regards Juan

[JohnC]

What was the reason you swtched cams? If I remember correctly it had something to do with detonation?

[dean]

Give us so MPG figures also. I would love to get rid of my CIS.
Thanks Dean

[Bruce M.]

Well, here are the highlights:

993 crank, 98 mm Mahle 7.5/1 pistons (3.45 liter displacement), Carillo rods and bolts, fancy valve springs and titanium retainers, twin plugs, Niresist rings, Carrera manifold, Motec 48 Pro Engine management, AirResearch TSO4 turbo, hand-fabbed stainless steel exhaust system, factory ZF-style LSD at 80% lock, stock tranny with a 935 pressure plate...

Detonation present with the old cams at high load, high rpms disappeared completely with EVO cams.

Gas mileage off boost in freeway cruise is mid to high 20s. Maybe a bit higher--can't say I've spent a whole tank at that level.

[JohnC]

A couple questions if you don't mind?

1) How would you describe your headers? A)Equal length yet short primaries or...... B)"shorties" with no primaries being equal length or.....C)long equal length primaries?

I assume the detonation is gone but I'm wondering what caused it to begin with. Perhaps the dynamic compression was too high? I.E the exhaust valve was closing early. This would imply that there exists more overlap in the EVO cams. Any ideas?

What are the EVO cam specs any way?

Thanks

[adamnitti]

GOOD LORD!!!

I'd love to hear some acceleration numbers when the engine's back in... That is some scary torque, man!!! Geez, I feel so meager and inadequate now.

[Bruce M.]

Adaminitti--that little blue guy is hilarious. No need to feel meager. Let me tell you that the agony of hop-ups humbles us all at some point.

As for acceleration figures, when I know more I'll tell you. Running at .8 bar from an idle with the old cams, the car did turn a 12.04 at 125 in the quarter on old street tires. I figure with the new cams, running at 1.2 bar and dropping the clutch a bit, I should be pretty easily deep into the 11s. I'm not much of a dragster, though. Track stuff is way better for me.

John--Don't know the specs of the EVO cams, but your supposition is exactly correct, according to Holcombe. I needed more overlap. Even with the more radical cams, they idle well within acceptable range.

As to the exhaust, it's short, un-equal length primaries, big secondaries, merged collector. A thing of beauty. In my opinion, worth every penny of the premium over GHL, etc. for high horsepower applications. For those that might be interested, Holcombe charges $3800 for these things. They are da bomb.

[930fan]

^%$#@#$ hell! You officially have a 700hp 911 and it's only a single turbo. Funny thing is, I don't think any of MoDe's twin turbos with the fabricated intake manifolds make more power than your theoretically inferior set up.

Btw, what signs did you have that it was detonating before and did it cause any damage? And please post some pics of your car if you can.

[Bruce M.]

Not bad, eh? Holcombe says that he's gotten more horsepower on single turbo set-ups, but not with the streetability of this car.

You could hear the detonation on the engine dyno as intermittent "crackling" at high rpms and boost, but not while the engine was in the car. Holcombe said I could just keep the boost down and live with it, and still have a monster, but of course I wasn't going to do that. I was far too stupid to do that, is another way of putting it.

I've got pictures of the car before the most recent work, but I must admit I have no idea how to post them. It looks like early 930, slate gray metallic, Fikse FM-10s, lowered about an inch. Hard to call any 930 a "sleeper", but its nothing out of the ordinary. Engine compartment has a nice powder coated fan, etc., but the 1100 c.i. intercooler covers just about everything.

[jkcrewsn]

You didn't mention what kind of intercooler you are running. If you don't mind, would you tell me who makes it, where you purchased it, and at what cost? And why did you go with the brand of turbo you are running? How does it compare with the KKK turbo? Is it comparable to a K-28, K-29 (you get the idea)? I am assuming it is a custom hybrid.

[juan ruiz]

Bruce ,What Brand of Intercooler are you Running?

[Bruce M.]

The interccooler is an 1100 cubic incher from Motorsport Design. Sorry, but by the time I pulled the trigger on that baby there were so many other things I was buying, getting credit for, etc., that I don't remember how much it eventually cost me. I vaguely remember getting a good deal on it, though.

I went with the AirResearch turbo because it was a more modern design than the KKKs I was considering, and as I recall had a good compromise between low-end and top-end power. It actually has been great. A turbo that can flow enough to top 700 horsepower on the engine dyno that also develops decent boost below 3000 rpm or so is fine by me. Plus, the longer stroke from the 993 crank and the extra half + point compression also helps the low end.